He was one of six children born to Leonce "Leon" and Anna Shelby Cagnolatti.
An excerpt from a piece written about Cosimo Matassa titled "Roll With It" stated that " Little Cag " shared Italian and African American parentage.
Cagnolatti began on trumpet around 1929 and played with Herbert Leary from 1933 to 1942, as well as off and on with Sidney Desvigne and Papa Celestin.
Cagnolatti was a recurring member of many of the major New Orleans brass bands; he worked in the bands of George Williams in the 1940s and 1950s, and with Alphonse Picou in the early 1950s.
He and Jim Robinson collaborated in the early 1960s, and he also recorded with Harold Dejan in 1962 and with the Onward Brass Band in 1968.